J. Mar. bioi.Ass. U.K. (1955)34, 565-577 565 Printed in

THE DICHOTOMOUS SPECIES OF IN BRITAIN

By Paul C. Silva Department of Botany, University of Illinois, Urbana

(Plate I and Text-figs. 1-5)

The name Codiumtomentosum(or its nomenclatural synonym C. dichotomum) has been applied to dichotomous representatives of the in the British Isles eier sincethe genus was establishedby Stackhousein 1797.The purpose ofthis paper is twofold:!to showthat three distinct speciesare involved; and to clarify the nomenclature. I am grateful to the directors and curators of the followingherbaria for the loan of specimens: British Museum (BM); RoyalBotanicGarden, Edinburgh (E); Farlow Herbarium, Harvard University (FH); University of Glasgow (GL); Royal Botanic Gardens, Kew (K); Rijksherbarium, Leiden (L); Linnean Society of London (LINN);University of Michigan (MICH); Botanical Garden (NY); University of Oxford (OXF);Museum National d'Histoire Naturelle, Laboratoire de Cryptogamie, Paris (PC); Marine Bio- logical Associatio~,Plymouth (PL); Naturhistoriska Riksmuseet, Stockholm (S); Trinity College,Dublin (TCD); University of California,Berkeley(UC); National Museum (US). Licjuid-:preservedand dried material, whi<;:hhas been placed in the Herbarium of the:University of California, was kindly provided by Dr Sheila Lodge, Dr !BertyMoss, Dr Mary Parke, Dr M::iirinde Valera, and Dr M. A. Wilson. Specialthanks are due to Dr Mary Parke for her sustained interest, encouragement, and help in this study. , Ii" . i : "(Sur.) Har~ot subsp. atlantit:um (Cotton) Silva, n.comb. i \ (Text-fig. 1) Codium'mucronatumJ. Ag. var.' atlanticum Cotton,11912, p. II4, pI. VII; pI. VIII, figs. 3-5." " \ C. fragile (Sur:) Hariot var.' typicum o. C. Schmidt subvar. atlanticum (Cotton) O. C. ,Schmjdt;'19,23, p. 47. '. " C. tomentosum Stackh, va~. atlanticum, (Cotton) Lily Newton, 1931, p. 106. C. fragile ($).Ir.) Hariot f. atlimticum (Cotton) Levring, 1937, p. 34~ C. atlanticum (Cotton) De Valera, 1939, p. 12. Thallus composed of one to several erect robust fronds arising from broad, spongy, basal disk; fronds 15-25 ( - 50) em high, dichotomously branched (to 9 orders), dichotomies at times telescoped to give fastigiate appearance;

37-2 566 PAUL C. SILVA

A

Text-fig. 1. Codiumfragile subsp. atlanticum. A, utric1es from tip; B, utric1es from base; C, D, utricles from middle of frond. A, B, D, Carna, de VaUra; c, Pon St Mary, Lodge. CODIUM SPECIES IN BRITAIN 567 branches terete (at times flattened at base), tapering from base (c. 10 mm diam.) to apex (2'5-4 mm diam.). Utricles irregularly cylindrical or clavate, (130 -) 17°- 330p. max. diam., 78o-II °° (- 1200) p.long, usually 3-5 x long as broad; apices slightly rounded, often terminating in a blunt (or occasionally sharp) point or umbo; wall of utricle c. 1'5p. thick, thicker at apex ( - 12P.)and often prolonging point into mucron 10-14p. long. Hairs (or hair scars) common, one or two per utricle, borne 130-200P. below apex. Gametangia ovoid, oblong, or fusiform, 80-130P. diam., 260-400p. long, one or two per utricle, each borne on protuberance near middle of utricle. Medullary filaments mostly 28-68 p. diam. Type. Rock pool, Roonah Point (opposite Clare Island), Co. Mayo, Eire, June 1910, A. D. Cotton (K). Geographic distribution. Western northward to western , Orkney Is., Isle of Man, Northumberland, Dorset, . Representative specimens examined. Ireland. CLARE: Kilkee, Oct. 1897, E. George (BM). GALWAY:Muigh Inis, Carna, Oct. 1943, M. de Valera. MAyo: Kinnacorra, Clare I., Aug. 19II, A. D. Cotton (BM); Roonah Point, June 1910, A. D. Cotton (K) (type). SLIGO: Sligo Bay, July 1850, Hennedy (GL). DONEGAL:Bundoran, July 1850, W. H. Harvey (TCD). ANTRIM: Portrush, Oct. 1858, Hennedy (GL); Giants Causeway, May 1910, A. D. Cotton (K); Larne, Aug. 1865, Mrs C. A. Johnson (BM). DOWN: Tara Point, Ards Peninsula, Aug. 1953, C. 1. Dickinson (K). Isle of Man. Bradda Head, Port Erin, April 1912, R.J. Harvey-Gibson (K); Port St Mary, May 195°, S. Lodge. Scotland. BUTE: Eilans, Cumbrae, Aug. 1891, E. Batters (BM); Keppel, Cumbrae, Apr. 1955, E. Conway (GL). ARGYLL:Iona, June 1826, R. K. Greville (E). ORKNEY:South Ronaldshay, Aug. 1891, G. W. Traill (BM); Pharay, Aug. 1880, Boswell (E); Westray, Aug. 1845 (TCD). INVERNESS:Mallaig, Aug. 1949, E. Conway (GL). . NORTHUMBERLAND:Berwick-upon-Tweed, Oct. 1949, B. Moss; Farne Is., Nov. 1952, B. Moss. DORSET:Swanage, Aug. 1894, E. Batters (BM).

Codium fragile (Sur.) Hariot subsp. tomentosoides (van Goor) Silva, n.comb. (Text-figs. 2, 3) Codium mucronatum J. Ag. var. tomentosoides van Goor, 1923, p. 134, fig. Ie. Thallus as in C. fragile subsp. atlanticum. Utricles irregularly cylindrical or more often clavate, frequently with broad constriction at or just below middle, (105 -) 165-325 (-4°°) p. max. diam., 550-1050p. long, usually 2'5-5'5 x long as broad; apices rounded-apiculate; wall of utricle c.l'5p. thick, thicker at apex (- 12p.), prolonging point into mucron up to 68p.long. Hairs (or hair scars) common, one or two per utricle, borne 160-260p. below apex. Gametangia ovoid, oblong, or fusiform, 72-92p. diam.,260-330p.long, 568 PAUL C. SILVA one or two per utricle, each borne on protuberance near middle of utricle (410-S60p. below apex.) Medullary filaments mostly 26-68p. diam. Type. Huisduinen, , 1900, Mrs J. L. Redeke-Hoek(specimen not located). In the absence of the holotype, I have selected as neotype a specimen from Helder, Netherlands, annotated by van Goor, in the possession of Prof. J. Heimans, Hugo de Vries Laboratorium, Amsterdam. Geographic distribution. Southern England, Scotland (Argyll), Ireland (Cork) France, Netherlands, Scandinavia.

A

B

Text-fig. 2. Codium fragile subsp. tomentosoides. A, utricles from tip; B, utricles from base; C, D, utricles from middle of frond. A, D, Steer Point, Hunt; B, c, Schouwen, Holland, Aug.1938,N.J. N. Kamp(L). CODIUM SPECIES IN BRITAIN 569

Representative specimens examined. England. :Trevone, Aug. 1953, open pool in current, mid-littoral, M. A. Wilson. DEVON:Bantham, July 1953, edge oflarge deep pool, M. A. Wilson; Yealm Estuary, near Steer Point, Nov. 1939, on oyster, G.D.Hunt (BM). DORSET:Kimmeridge Ledges, Apr. 1955, C. 1. Dickinson (K). SUSSEX:Elmer Sands, 3 miles E. of Bognor, Aug. 1954, cast up, R. W. J. Keag (K). Scotland. ARGYLL: Loch Sween, June 1953, E. Conway (GL), Ireland. CORle Lough Ine, July 1950, S. Lodge.

Text-fig. 3. Codiumfragile subsp. tomentosoides.Lough Ine, Lodge. A,utticles from tip; B,utticles from middle of frond. I.'

Codium tomentosum Stackhouse (Plate I, fig. I; Text-fig. 4) Stackhouse 1797, p. xxiv. 1795, p. 21 (sub FucUs tomentosus Hudson excl. syn. Linn.). Fucus tomentosus Hudson var. marginifer Turner, 18II, p. I. Thallus composed of one to several erect fronds arising from br9ad, spongy, basal disk; fronds 20-4° em high in pools, 45-60 (- 9°) cm high in deep water, dichotomously branched (to nine orders), dichotomies at times tele- scoped to give subfastigiate appearance, at other times distant (internodes 57° PAUL C. SILVA

7-8 em long), rarely proliferous; branches mostly terete but frequently flattened at dichotomies, 3-S mm diam. in lower parts, to 8 mm at dichoto- mies, attenuating to I'S-2 mm at apices, terminal segments often long (S-II em). Utricles cylindrical or slightly clavate, often with hip-like en- largementnearbase,(6S- ) 100-200(- 27S)P,max. diam., (420- ) soo-800 (- 10SO)P, long,(3-) 4-7 (-9) x longasbroad;apicesroundedor tending to be pointed; apicalwall usually moderatelythickened (-44p,), lamellate, at times introrsely umbonate and/or extrorsely bluntly PQinted. Hairs (or hair

~:!

t)j

A

.> .;,. ?lft ~,,;,,~"""','.'i"~~Ifj ;.:[

Text-fig. 4. Codium tomentosum. A, utdcles from tip; B, utricles from base; C, D, utricles from middle of frond. A-G, Carna, de Valera; D, Wembury, Ryder. CODIUM SPECIES IN BRITAIN 571

scars) common, numerous, borne at conspicuous distance below apex (13°- 2351-"),forming collar below broadest part of utricle. Gametangia ovoid, oblong, or fusiform, 5°-11°1-" diam., 165-34°1-"long, one to four per utricle, each borne on prominent protuberance one-half to two-thirds distance below apex. Medullary filaments mostly 20-5°l-"diam. Type. 'On the Devonshire and Cornwall Coasts: on the Long Rock between and Pensance1 plentiful. Hon. Mr. Wenman' (specimen not located). In the absence of the holotype, I have selected as neotype a specimen in the Linnean Society collected at Acton Castle, presumably by Stackhouse. Geographicdistribution. Western Ireland, Orkney Islands, southern England, , Netherlands south~ard to Morocco, Islands, Algeria. Representative specimensexamined. Ireland. CORK:Bantry Bay, July 1808, Miss Hutchins (K) (type of Fucus tomentosus var. marginifer Turner). CLARE: Kilkee, July 1833, W. H. Harvey (TCD, K, NY). GALWAY:Muigh Inis, Carna, Oct. 1943, M. de Valera; Renvyle Point, Jan. 1831, R.J. Shuttleworth (BM). MAyo: Clare Island, Aug. 1911, A. D. Cotton (BM, K, NY). SUGo: Sligo Bay, July 1850, Hennedy (GL). DONEGAL:Malin Head, July 1897, M. R. Clarke (FH, NY). ANTRIM:Ballycastle, 1797-98, R. Brown (BM). Scotland. ORKNEYISLANDS,J.H. Pollexfen (BM). England. CORNWALL: St Mary's, Scilly Islands, Sept. 1953, E. Conway (GL); Acton Castle, Stack- house (LINN) (neotype); King's Cove, June 1799, D. Turner (BM, K); Mullion Cove, Jan. 1932, Lyle (BM); Gerrans Bay, E. M. Holmes (BM); West , Nov. 1952, M. Parke (PL). DEVON:Wembury, Oct. 1953, F. G. C. Ryder (PL, UC); Salcombe, May 1953, D. Ballantine (PL); Torquay, Wyatt's Algae Danmonienses no. 35 (BM, E, K, L, NY, TCD, UC); Exmouth, 1864, Mrs C. A.Johnson (BM). DORSET:Weymouth, Sept. 1892, E. Batters (BM); Swanage, Aug. 1894, E. Batters (BM). SUSSEX:Brighton, July 1889, Miss Palmer (BM). Channel Islands. Guernsey, Aug. 1840, Lady Mansell (BM). A plant of C. tomentosum in which the dichotomous branches bear numerous simple and forked proliferations was described by Turner as a variety (margini- fer) of Fucus tomentosus.This proliferous condition is rare in Codium tomentosum compared to C. vermilara.

Codium vermilara (Olivi) Delle Chiaje (Plate I, fig. 2; Text-fig. 5) Lamarckia vermilara Olivi, 1792, p. 258, pI. VII. Myrsidrum vermilara (Olivi) Rafinesque, 1810, p. 98. Codium vermilara (Olivi) Delle Chiaje, 1829, p. 14. Thallus composed of one to several erect fronds arising from small, spongy, basal disk; fronds 10-45 cm high, closely dichotomously branched (to 10 orders), often irregularly so, branches frequently bearing simple or forked proliferations; branches terete, tapering from c. 4 mm at base to 1'5-2 mm

1 Old spelling of (ED.). 572 PAUL C. SILVA at tips, terminal segments usually short. Utricles clavate to pyriform, (65 - ) 9°-24° (-340)fLdiam., (33°- ) 400-650 ( -Iooo)"dong, 1'5-4'5 (-7) x long as broad; apices rounded; apical wall slightly to moderately thickened, 5 to 15 ( - 50) fL,lamellate. Hairs (or hair scars) common, numerous, borne on shoulder of utricle 60-11°fL below apex. Gametangia oblongto fusiform, (52- ) 60-80 (-96) fLdiam., 200-290fL long, one to four per utricle, each borne on protu- berance one-half to two-thirds distance below apex. Medullary filaments mostly 18-45fL diam. Type. No specimens mentioned in original description. I have selected as neotype a specimen in the Herbarium of the University of California at Berkeley distributed as Flora Exsiccata Austro-Hungarica no. 794 under the name C. tomentosum, collected by Zay atPortore, Croatia.

Text-fig. 5. Codiumvermilara. Wembury, Ryder. A,utricles from tip; B, utricles from base; c, utricles from middle of frond. CODIUM SPECIES IN BRITAIN 573

Geographicdistribution.Ireland (Galway,Antrim), Scotland(Argyll),south- ern England, Channel Islands, Norway, France southward to Morocco, Mediterranean, including Adriatic. Representativespecimensexamined. Ireland. GALWAY:Galway, McCalla (TCD). ANTRIM:Portrush, 1835, D. Moore (K, TCD); Cushendall, W. H. Harvey (BM). Scotland. ARGYLL: Portnahaven, Islay, 1826, J. Chalmers (BM, GL, K). England. DEVON(north coast): Ilfracombe, Oct. 18°7, R. Hare (BM). CORNWALL:Penzance, M. P. Merrifield(BM); St Michael's Mount, June 1799, D. Turner (K); Acton Castle, June 1798, Stackhouse (LINN); Falmouth, F. W. Smith (BM); Gerrans Bay, E. M. Holmes (BM). DEVON(south coast): Wembury, Oct. 1953, F. G. C. Ryder (PL, DC), Sa1combe,July 1941, M. Parke (PL); Harbrick, Torbay, March 1833, Mrs Griffiths(BM); Torquay, Lyon (BM); Exmouth, Miss Baker (K); Sidmouth, Nov. 1829 (TCD). DORSET:Weymouth, Dec. 19II, A. D. Cotton (K); Swanage, E. M. Holmes (DS). HANTS:West Cowes, Isle of Wight, Count Pouliatine(BM). Channel Islands: Jersey, F. P. Girdlestone(MICH).

DISCUSSION The presence in the British Isles of a Codiumwith mucronate utricles was first demonstrated by Cotton (1912),who described C. mucronatumvar. atlanticum. This entity is herein referred to C. fragile in accordance with the general agreement that the latter is conspecific with C. mucronatum.Taxonomic treatment of C. fragile is complicated by the followingfactors: (i) the species in the broadest sense may be considered a complex assemblageof populations and series of populations, some of which are morphologicallyhomogeneous and others heterogeneous; (ii) evidence is present for hybridization or gene flowbetween plateaus of morphologicaluniformity; (ill)the specieshas by far the most extensive geographic distribution of anyCodium, occurring on all continents; (iv)unusual physiologicaladaptability is implied by the variety of habitats, from the sublittoral to the midlittoral, from surf-swept rocksto quiet shell-mud flats; (v)the specieshas the vigour and adaptabilityof a weed and is spreading rapidly in such.places as Scandinavia, France and Spain. A com- plete considerationof C.fragilewillbe presented in a forthcomingmonograph of the genus. For the present accountit is sufficientto state that in the British Isles there are two seriesof populations of mucronate Codium,each relatively uniform morphologically, which I consider best treated as subspecies of C. fragile. The present centres of distribution ofC. fragile are the Pacific and Sub- antarctic oceans. By far,the greatest morphological heterogeneity occurs in . In fact, almost all subspecies (geographicallydiscrete series of mor- phologicallyuniform populations) can be matched by one or more Japanese collections. It is possible that C. fragile subsp. atlanticumwas introduced 574 PAUL C. SILVA from the Pacific within historical times. According to Cotton (1912, p. II6) it was collected at Bantry Bay by Miss Hutchins (c. 1808?). Another early collection is one made by Greville on the island of Iona in 1826. Chalmers (Algae Scoticae Exsicc. no. 13, 1826) stated that Codium was unknown in Scot- land before 1825, when it was discovered on Iona by Berkeley. This subspecies seems to be spreading: Cotton (p. II9) noted that it probably was established on the Isle of Man in 1900, and the presently cited Northumberland and Swanage collections are the first published English records. (The Swanage record seems out of range and some doubt is thus raised as to the correctness of the locality.) The earliest known collection from Norway is dated 1918 (Hussay near Molde, N. Wille, S). Codium fragile subsp. tomentosoides seems definitely of very recent occur- rence in . It was first collected in Holland in 1900 (van Goor, 1923, p. 133), in 1920 (Rosenvinge, 1920, p. 131), Sweden in 1938 (Brandholmen near Lango, BohusHin, C. Engblad, S), Norway in 1952 (Bratvaer near Kristiansund, H. Printz, DC), Atlantic France in 1946 (Iles de Glenan and Concarneau, R. Lami, PC), and England apparently in 1939 (Yealm Estuary, at Steer Point, S. DEVON,O. D. Hunt, BM). The place of origin seems most likely Japan. These two subspecies of C. fragile are easily 9.istinguishable anatomically. The apices of the clavate-cylindrical utricles of subsp. atlanticum are rounded, extrorsely umbonate, or provided with a very short, usually blunt mucron. The utricles of subsp. tomentosoides tend to be shorter and stouter, have a pronounced median or submedian constriction, and are sharply mucronate. Subsequent to Cotton's demonstration of C. mucronatum (C. fragile) in the British Isles, the name C. tomentosum remained to encompass the non- mucronate dichotomous forms. That two distinct species are involved has not been recognized heretofore. Codium tomentosum and C. vermilara differ sufficiently in habit. to be dis- tinguishable in the field with a little practice. In C. tomentosum branching is usually regularly dichotomous and the branches are often fla~tened at the dichotomies; the base of the thallus is thick and terminal segments are often long. In C. vermilara branching is usually somewhat irregular, often prolife- rous, at times divaricate, and the branches are strictly terete; the base of the thallus is not noticeably thick and terminal segments are usually short. C. tomentosum is often more robust and more distantly branched than C. ver- milara. Herbarium specimens are not so readily distinguishable on the basis of habit. Anatomically the two species are unmistakable. The position of hair scars is significant: in C. tomentosum they are well below the apex and at a constric- tion, so that the utricle expands above them; in C. vermilara they are usually high on the shoulders of the utricle, or iflower, never at a constriction, so that the utricle tapers rather than expands immediately above them. The average COD/UM SPECIES IN BRITAIN 575 length/breadth ratio isgreaterin C. tomentosumthan in C.vermilara.Thickened apicesare commonin both species:in C. tomentosumablunt point isfrequently formed while in C. vermilarathe thickening is more uniform. The cylindrical or narrowly clavate utricles of C. tomentosumare in contrast to the clavate or pyriform utricles common in C. vermilara. C. vermilara is common throughout the Mediterranean (including the Adriatic). In the Atlantic it extends from Morocco to France and the British Isles. Aalesund and Kristiansund in Norway constitute the most northerly records. C. tomentosum,on the other hand, is primarily an Atlantic species, occurring from the British Isles south along France, Spain, and Portugal to Morocco. It occurs in the Mediterranean only along the Algerian coast. Heretofore, C. tomentosum.has been credited with cosmopolitan distribution, but careful study revealsthat more than thirty distinct specieshave been con- fused under this name. Separating the two non-mucronate species in the British Isles was much easier than deciding their correct names. Applicationof the type method was made difficult by the absence of holotypes. The earliest name applicableto a dichotomous Codium would seem to be Hudson's Spongia dichotoma (1762, p. 489) or its isonym Fucus tomentosus(1778, p. 584). However, as Linda Newton (1953,p. 4°3) has explained,Hudson's binomialsmust be con- sidered illegitimate synonyms of F. elongatusL. (the type of which is referable to Himanthalia),which Hudson cited as a synonym. This unfortu- nate circumstance resulted from the erroneous citation by Linnaeus of Morison's Fucus spongiosus teres ramosior viridis erectis (1699, p. 647, sect. 15, pI. 8, fig. 7), which misled Hudson to cite the Linnaean binomial. Miss Newton concluded, as I have concluded, that Codium tomentosum Stackhouse (1797) may be treated as a new name (rather than a transfer of Fucus tomentosus Hudson) in accordance with Art. 81 of the International Code of Botanical Nomenclature, inasmuch as Stackhouse explicitly excluded Fucus elongatus L. from his concept of Codium tomentosum. In determining the application of the name Codium tomentosum Stackhouse, one is faced with the problem that Stackhouse had both non-mucronate species in hand, as shown by specimens in the Linnean Society. His description fits either species; the plant figured on Plate VII of his 'N ereis' is very likely C. vermilara. On the basis of the following considerations, however, it seems advisable to fix the application of C. tomentosum as delimited herein: (i) C. tomentosum, rather than C. vermilara, was the basis of treatments given by Turner (18Il, p. I, pI. 135), Harvey (1846, pI. XCIII),and Cotton (1912, p. Il3, pI. VIII, figs. 1,2); (ii) shifting the name C. tomentosum to C. vermilara would leave C. tomentosum as circumscribed herein without a name. It is of historical interest to determine the identity of Morison's, Ray's and Hudson's plants. The two specimens in Herb. Morison (OXF), r~presenting Fucus spongiosus teres ramosior. . . and Fucus spongiosus teres viridis. . .(1699 576 PAUL C. SILVA p. 647,nos. 7, 8), are both referableto C. iomeniosum.The Spongiadichoiomos compressa,ex viridi splendens(Ray, 1724,p. 29, no. 4) in Herb. Sherard (OXF) is also representative of C. tomentosum. Hudson had both species in hand, judging from specimens at Kew, the British Museum, and Edinburgh. Codium vermilara, occurring as. it does in the Mediterranean, might be expected to have been described early. Although no authentic specimens have been located, the identity ofOlivi's Lamarckiavermilara(1792),to judge from the description and figure,seems certain. While the lackof any reference to Olivi raises doubt that CodiumvermilaraDelle Chiaje (1829) should be considered a new combination, closer study of the rare Delle Chiaje work answers the question. It is clear from Delle Chiaje's choice of epithets in Codiumthat he wasfollowingRafinesque(1810,p. 97),who in turn cited Olivi. Thus it seems proper to use the binomial C. vermilara(Olivi) Delle Chiaje.

SUMMARY

The dichotomous species of Codium in the British Isles are described, com- pared, and illustrated. These include C. fragile subsp. atlanticum, C. fragile subsp. tomentosoides, C. tomentosum and C.vermilara.

REFERENCES COTTON,A. D., 1912. Clare Island Survey. Marine algae. Proc. R. Irish. Acad., Vol. 31, Part 15, 178 pp., II pIs. DELLE CHIAJE, S., 1829. Hydrophytologiae Regni Neapolitani. 27 pp., 100 pIs. Naples. , DE VALERA,M:, 1939. Some new or critical algae from Galway Bay, Ireland. K.

fysiogr.Siillsk. Lund Forh., Bd. 9, NO.9, 14pp. '. 'HARVEY,W. H., 1846. Phycologia Britannica.-Vol. I, xv, viii pp., pIs. I-120B. London. HUDSON,W., 1762. Flora Anglica. \ 506 pp. London. - 1778. Flora Anglica. 2nd ed. 690 pp. London. LEVRING,T., 1937. .Zur Kel'lntnis der Algenfiora der norwegischen Westkiiste. Lunds Univ. Arsskr., N.F. Avd. 2, Bd. 33, No.8. 148 pp., 4 pIs. MORISON,R., 1699. PZaniarum Historiae Universalis Oxoniensis Pars Tertia.... 657 pp., 166 pIs. Oxford. NEWTON,LILY, 1931. A Handbook of the British . 478 pp. London. NEWTON,LINDA, 1953. Marine algae. Sci. Rep.John Murray Exped., Vol. 9, NO.5, pp. 395-420, 4 pJs. , OLlVI, G., 1792. Zoologia Adriatica. . .. 334 PP., 9 pIs. Bassano. RAFlNESQUE,C. S., 1810. Caratteri di Alcuni Nuovi Generi e Nuove Spede di Animali e Pianti della Sicilia. ." 105 pp., 20 pIs. Palermo. RAy, J., 1724. Synopsis Methodica Stirpium Britannicarum 3rd ed. 482 pp. London. . ROSENVINGE,L. K., 1920. am nogle i nyere Tid indvandrede Havalger i de danske Farvande. Bot. Tidsskr., Bd. 37, pp. 125-35. SCHMIDT,.0. C., 1923. Beitriige zur Kenntnis cler Gattung Codium Stackh. Bibl. bot., Stuttgart, Heft 91, '68 pp. ' ,

CODIUM SPECIES IN BRITAIN 577

STACKHOUSE, J.,1795-1801. Nereis Britannica. ... xl, 112 pp., 17 pIs. Bath. TURNER, D., 1811. Fuci Vol. III. 148 pp., pIs. 135-96. London. VAN GOOR, A. C. J., 1923. Die holHindischen Meeresalgen (Rhodophyceae, Phaeophy- ceae und Chlorophyceae) insbesondere der Umgebung von Helder, des Watten- meeres und der Zuidersee. Verh. Akad. Wet. Arnst., Sect. 2, Deel 23, No.2, 232 pp.

EXPLANATION OF PLATE I

Fig. 1. Codium tomentosum. Small deep pool, Church Reef, Wembury, Devon, Oct. 1953, F. G. C. Ryder (UC). Fig. 2. Codium vermilara. Large pool, mid-littoral, Church Reef, Wembury, Devon, Oct. 1953, F. G. C. Ryder (UC).